Abstract

Based on the results obtained for C–N and Si–C–N films, a systematic investigation of reactive magnetron sputtering of hard quaternary Si–B–C–N materials has been carried out. The Si–B–C–N films were deposited on -type Si(100) substrates by dc magnetron co-sputtering using a single C–Si–B target (at a fixed 20% boron fraction in the target erosion area) in nitrogen-argon gas mixtures. Elemental compositions of the films, their surface bonding structure and mechanical properties, together with their oxidation resistance in air, were controlled by the Si fraction (5–75%) in the magnetron target erosion area, the Ar fraction (0–75%) in the gas mixture, the rf induced negative substrate bias voltage (from a floating potential to ) and the substrate temperature . The total pressure and the discharge current on the magnetron target were held constant at and , respectively. The energy and flux of ions bombarding the growing films were determined on the basis of the discharge characteristics measured for the rf discharge dominating in the deposition zone. Mass spectroscopy was used to show composition of the total ion fluxes onto the substrate and to explain differences between sputtering of carbon,silicon and boron from a composed target in nitrogen-argon discharges. The films, typically thick, possessing a density around , were found to be amorphous in nanostructure with a very smooth surface and good adhesion to substrates at a low compressive stress . They exhibited high hardness (up to ) and elastic recovery (up to 88%), and extremely high oxidation resistance in air at elevated temperatures (up to a substrate limit).

Received 03 March 2005Accepted 01 August 2005Published online 17 October 2005

Acknowledgments:

This work was supported by the Ministry of Education of the Czech Republic through Project No. MSM 4977751302. The authors would like to thank Professor A. Cavaleiro at the University of Coimbra (Portugal) and Dr. M. Kumagai at Kanagawa Industrial Technology Research Institute for their valuable comments, and K. Yabuta and Y. Ito at Kanagawa High-Technology Foundation for their technical assistance in HRTEM observation.